1. Field of the invention
The present invention relates to an image forming system, more particularly, an image forming system which combines an image forming apparatus such as a copying machine and a printer and a sorter having a plurality of bins which sort sheets.
2. Description of Related Art
Recently, in image forming apparatuses, such as a copying machine and a printer, various sorters which sort image-formed sheets in page order or by each page.
Conventionally, as this kind of sorter, Japanese Patent Publication No. 61-57262 which has a bin assembly comprising a plurality of bins which are movable up and down by one pitch for sorting sheets onto the bins (reciprocating distribution) is well-known.
In this kind of reciprocating distribution sorter, a motion of a bin assembly is efficient, thus, copy productivity is improved. However, when a last sheet is distributed to the bin, it is happened that the bin assembly is stopped at a lower position, and it becomes difficult for an operator to take out sheets. That is, the bin assembly is usually at stand-by at a lower home position, and moves up when an odd number of sheets are sorted, and moves down when an even number of sheets are sorted. After sorting of even number of sheets is finished, the bin assembly is set at the lower position, therefore, an operator has to bend himself/herself to take out the sheets.
On the other hand, Japanese Patent Publication No. 4-23885 discloses a technique that after sorting sheets, with operating a key, bins are moved by one bin to a position where an operator can take out sheets easily. In this technique, however, it takes long time to take out sheets, therefore, it becomes inefficient.